Risk Assessment And Early Emergency Warning Plans For Water Pollution Accidents In Long Distance Water Transfer Projects

The water resources of China are unevenly distributed with respect to both time and space,and restrict the development of social and economic in scarce water areas seriously.In recent years,the construction and commissioning of long distance water transfer projects become an important engineering measures to alleviate water shortage in the northern city.The long distance water transfer projects had a longer main canal,open water and many complex hydraulic structures,parts of industrial enterprises along the canals.While main canals also take the function of shipping,so it is prone to polluted by accidents.After the incident,the risk is need to evaluate in time.It develop a reasonable early warning emergency plan that based on pollutant transport and diffusion characteristics,in order to minimize the adverse impacts of the accidents.In the dissertation,taking canals in Jiangsu Province of the eastern route of South to North Water Project as an example,a reasonable risk assessment method and early warning emergency plans system of water pollution accident are put forward,by considering the canals characteristics,water quality and risk types of long distance water transfer projects.The main research work and results include the following aspects:?1?A risk assessment method,based on the DPSIR model,is put forward to evaluate the risk of water pollution accidents in long distance water transfer projects.It shows mechanism of risk level under the influence of the pollution ways,type,acceptors stats and impacts,safety responses.The index system including 15 indicators,and that computational model is constructed by considering the characteristics of long distance water transfer projects.Weight of each indicators are determined by experts based on their knowledge.The comprehensive risk assessment is carried out by indicators value and weight.The method is applied to evaluate the risk level of the sudden pollution in bridge accidents of eastern route.Risk level determination is important to guide the agency coordinated response and effective measures to carry out to resistant the sudden pollution incidents.?2?The prediction formula of parameters when soluble and floating oil pollutants in water canals are put forward.Three parameters are proposed to represent the characteristics of soluble pollution,peak pollutant transport distance,peak concentration and longitudinal length,respectively.By the numerical simulation,filed experiment test and physical model validation,the prediction formula of pollutant characteristics indicators are put forward,which can be widely used in non-braided canals,series canals and branching canals.To propose five characteristic parameters for the oil pollution,oil film transport distance,oil film longitudinal length and braided width and oil separated ratio under the oil spill accidents.Based on physical model experiment and numerical simulation,oil film thickness in water surface is proposed.And the oil film is diesel> lubricating oil > waste oil> vegetable oil.While it can be calculated the limited expansion area of burst oil spill in the no-border area based on the measured thickness.The paper proposes the migration regularity of diesel,lubricating oil and vegetable oil in canals,and the oil film transport distance that is not affected by oil type are 1.15 times to the middle velocity of flow.The oil film longitudinal lengths of diesel oil,lubricating oil and vegetable are 0.5 times,1.39 times and 1.7 times to the middle velocity that follow the time respectively.The two characteristic parameters are not affected by oil spills level and spill location.Wind has a large effect on the oil film transport distance,whereas no effects on the longitudinal length.According to multiple types of braided canals,the paper put forward the oil separate width formulas under the combination of numerical simulation and physical model experiments.And oil width is affected by branching patterns,and it is related to upstream and mainstream film width,the width and branching tributaries flow ratio.The paper proposes theoretical derivation method of oil separated ratio,and proposes a prediction formula of k_oil=Bs/B_u-oil.This formula is applicable to any type of braided canals.?3?A system of risk assessment and early emergency warning plans of water pollution accidents in long distance water transfer projects,which based on characteristics values prediction of transport and diffusion of pollutants.The system combines the characteristics and requirements of the water pollution accidents of long distance water transfer projects closely,and integrates the methods and models of risk assessment and pollution prediction,and the way to construct indicators for the early warning and multi-level emergency plans.Under the system decision makers can evaluate risk rapidly,then put forward reasonable warning and response plans.It also can provide scientific decision support to the water pollution accidents in long distance water transfer projects.?4?Under the emergency control principle,the segmentation index calculation model of water supply and after the disposal water supply principles,an emergency response system is constructed.As an example of the first phase of eastern route of South-to-North water transfer project in Jiangsu province,the risk assessment and early warning systems are applied to resistance water pollution accidents,and then developed the early warning emergency plans system of eastern route in Jiangsu province based on the results of river division that Combines the stress control principles,emergency water supply schedules and disposal water supply principles.The dissertation constructs a system combined risk assessment,pollution prediction and early warning emergency responses,and then it provide decision support for pollution control and emergency response of water pollution accidents in long distance water transfer projects.